Conditions were so harsh on the ship that one member of the 24-person crew reportedly committed suicide by jumping overboard. Another was killed by pirates.

Over the weekend, troops from the Puntland Maritime Police Force rescued the 22 hostages remaining on the Panama-flagged vessel, ending the longest time anyone has been held hostage by pirates, according to Michael Howlett, deputy director of the International Maritime Bureau.

"We are greatly relieved to hear that they are safe after their terrible ordeal," said Peter Swift, chairman of the Maritime Piracy Humanitarian Response Programme, which has been tracking the ship's saga.

JUST WATCHED

Couple held captive by pirates speak out

MUST WATCH

JUST WATCHED

New weapon to fight pirates

MUST WATCH

New weapon to fight pirates02:10

PLAY VIDEO

Sunday's rescue was the result of a two-week operation, the International Maritime Bureau said.

Mohamed Abdulrahman, director of the maritime force that led the mission, said Monday that the rescued hostages -- who hailed from Yemen, India, Pakistan, Ghana, Sudan and the Philippines -- were in good health at a military base in Puntland, a semiautonomous region of Somalia.

They showed signs of physical abuse and illness after their time in captivity, the International Maritime Bureau said.

"We hope that both public and private organizations will work to ensure that the released hostages, as well as their families, receive all the necessary support and assistance they will require both immediately and longer term as they recover from the trauma and deprivation that they have suffered since being kidnapped," Swift said.

In March 2010, pirates hijacked the ship, which had been transporting mechanical equipment and was en route to the United Arab Emirates, the European Union Naval Force Somalia reported at the time.

"Whilst this is a successful rescue operation, our thoughts are with the remaining 139 hostages still held by pirates, 28 of whom have been there for just under two years," the International Maritime Bureau said in a statement.

On Sunday, officials from the bureau, which monitors pirate attacks, said that heavily armed pirates had kidnapped four people after attacking an Italian supply vessel off the coast of Nigeria.

In October, the bureau reported that sea piracy had fallen to its lowest level worldwide since 2008 as a result of increasing policing by international naval forces.